The Rail Safety Improvement Act of 2008, as enacted by the U.S. Congress, requires all Class I railroads and passenger rail operators to implement a mandatory Positive Train Control (PTC) collision avoidance system. PTC introduces continuous global positioning system (GPS) based location and speed tracking, with sophisticated on-board wireless technology that enables enforcement of vehicle movement in a rail system from a centralized control center. PTC utilizes a mapping of the tracks in a rail system and of assets located along the tracks, such as rail crossings, signals, mile markers, and the like. The mapping information is configured into track data files or subdivision files for each segment of track in the rail system.
The PTC track data must be verified prior to its use. The verification process requires that every feature in the PTC onboard track data is verified to have an accurate position to within 2.2 meters of the position reported by a precision GPS unit.
Current processes for track-data verification require a vehicle to be driven along a rail system to each of a plurality of assets whose GPS location is to be verified. The vehicle is moved along the tracks to align a precision GPS unit mounted on the vehicle or towed therebehind alongside the asset, e.g. the GPS unit is positioned such that a line drawn between the GPS unit and the asset is generally perpendicular to the length of the tracks. This alignment is typically visually aligned or “eyeballed” by an operator traveling in the vehicle.
Depending on the location of the GPS unit relative to the operator, the alignment may be verified by aligning the asset with a window of the vehicle or a mark placed on or adjacent to the window. Or the operator may exit the vehicle to view the asset and GPS unit and to instruct a driver of the vehicle to move the vehicle into proper alignment, such as when the GPS unit is mounted on a trailer towed behind the vehicle. Such as verification system is time consuming, prone to operator error, and may expose the operator to dangerous conditions.
Additionally, the current process requires a representative of the Federal Railroad Administration (FRA) to witness the validation. This can create scheduling conflicts or difficulties and is an inefficient use of manpower resources.